Ignore is a shortform variant of QUALITY, used to set the temporary bad quality data flag of points within a binned dataset (most significant bit of the QUALITY byte).
IGNORE = QUALITY IGNORE OVERAs with QUALITY the user is able to select axis ranges; data value ranges; and to specify a particular existing quality value, to choose the points in the dataset to be effected.
See QUALITY for full details of the parameters and their keywords.